Ionising Radiation and Nuclear Reactions

Flashcards about Ionising Radiation and Nuclear Reactions

Atoms are the basic unit of matter. They contain a nucleus made up of _ and , surrounded by a negatively charged ‘cloud’ of _.

protons, neutrons, electrons

A nucleus consists of and __

protons, neutrons

Protons and neutrons make up the nucleus, so they are known as

nucleons

Each type of nucleus is known as a .

nucleide

The atomic number (Z) shows the number of _ in an atom.

protons

An increase in protons means an increase in __and ___

mass, charge

Atomic Mass (Mass Number) A is the sum of protons and _.

neutrons

The magnitude of the electric charge carried by a single electron or proton is called .

Elementary Charges

If the number of positive charges is the same as the number of negative charges, the atom is .

neutral

Ion: an atom that has lost or gained _.

electrons

An element which has the same number of _ but a different number of _ is called isotopes

protons, neutrons

In a stable nucleus, the nucleons (___and _) are held together tightly and don't break up.

protons, neutrons

In smaller nuclei, the number of neutrons to protons have a N/Z ratio of _

1 : 1

If a nuclide is not stable (radionuclide), it is considered to be .

radioactive

Radioactive: substances that have nuclei with an excess of energy and spontaneously emit ___ to reduce the excess energy

radiation

Alpha radiation (particles) are helium nuclei, which are made up of two protons and ____ neutrons strongly bound together

two

Beta-negative radiation (particles) are __emitted from the nucleus.

electrons

During collisions, gamma rays _ material

absorb

Radiation detectors (Geiger counter) are used to detect ___as it is invisible.

ionising radiation

Radiation spreads out in all directions (like a sphere) and is inversely proportional to ___.

radius squared

Layers of shielding are added (creating a thicker shield) and the intensity drops ___.

exponentially

The thickness is known as the ___ layer (HVL)

half value

The original unstable nucleus decays to produce a _and at least one other particle.

daughter nucleus

Nuclear decay is , but it can be artificially started.

spontaneous

The mass defect is the difference between the mass of a and the sum of the masses of the particles from which it is made.

nucleus

Binding energy is the amount of _required to break apart a nucleus into its individual protons and neutrons by overcoming the forces that hold it together

energy

all objects having mass (or massive objects) have a corresponding ___ energy. Even when they are stationary

intrinsic

Binding energy per nucleon: is the binding energy divided by the number of _ in the nucleus of an atom

nucleons

Electron volt: a unit of energy defined as the work done on an electron to move it through an electric potential of ___.

1volt

Fission reactions produce a lighter particle that collides with a heavier parent nucleus, making it more __.

unstable

For atoms on the ____ side of the stability chart, fission is more likely.

right

In a nuclear reactor, chain reactions are controlled by absorbing excess neutrons using ‘control rods’ made of ___

cadmium

Nuclear fusion releases more _than nuclear fission, as a greater percentage of the mass is converted to energy

energy

With Nuclear Fusion, the new nucleus is now more stable as its _ energy per nucleon is greater

binding